Environmental Sciences: Towards a Sustainable Future Chapter 2

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Environmental Sciences Towards a Sustainable
Future Chapter 2

• Ecosystems Units of Stability

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This Chapter Is About Ecosystem Structure

• The major ecosystem components.
• Interrelationships between ecosystem components.
• Limiting factors.
• Symbiotic relationships.
• Human impacts on ecosystem structure.

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Species

• Total population
• Of any organism
• Interbreeds
• Reproduces
• Examples
• Florida panther
• Prairie smoke

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Ecosystem

• Grouping of plants and animals
• Interacting
• With each other
• And their environment
• Examples
• Tall grass prairie (Iowas ecosystem)
• Tundra

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Ecological Principles DICE
Diversity (Bio) Interrelationships Cycles Energy
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Inorganic and Organic

• Inorganic
• Oxygen
• Carbon dioxide
• Nitrogen
• Water
• pH

• Organic
• All living things
• Products of living things

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How Ecosystems Are Formed
Abiotics
(moisture and temperature)
predict
( moisture forest)
Plants
(temperature forest type)
predict
Animals
(lynx or bobcat)
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Abiotic

• Nonliving things
• Examples
• Rainfall
• Temperature
• Salinity
• pH
• Rocks
• Water

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Abiotic Effects in Ecosystem DevelopmentDetermine
d by Amount of Rainfall
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Law of Limiting Factors
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Limit of Tolerance

• Point at which an organism just barely survives
• Absolute limit that the organism can survive
• Includes high and low value of variable
• Impacts
• organism faces increasing stress
• Organism declines in population
• If the change is gradual enough, the species will
  adapt

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Optimum

• Best condition for an organism
• The amount of a required factor which is most
  favorable for an organisms growth and
  reproduction

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Ecosystems
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Trophic Levels
Third-order Consumer
Secondary Consumer
Primary Consumer
Producer
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Autotrophs
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Match Organisms With Trophic Level(s)
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Match Organisms With Trophic Level(s)
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Trophic Level Energy Exchanges
Third-order Consumer
1Kcal
- 10x
Secondary Consumer
10 Kcal
- 10x
Primary Consumer
100 Kcal
- 100x
10,000 Kcal
Producer
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Trophic Levels Pyramid of Biomass
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Trophic Levels Pyramid of Energy
Only 10 of biomass energy is passed on to next
energy level
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Food Webs
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Trophic Relationships Among Producers and
Consumers
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Trophic Categories and Terminology
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Symbiosis Living Together

• Mutualism
• Commensalism
• Parasitism (external, internal, social)

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Parasites and Humans
Go to this web site to learn about dog tapeworms
and roundworms
http//www.mmpvets.co.uk/roundworms.htm
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How Human Ecosystems Are Different

• Produce abundant food
• Control water flow rate and direction
• Overcome predation and disease
• Construct our own ecosystems
• Overcome competition with other species

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Calculate Your Own Ecological Footprint
Go to this web site.
http//www.simpleliving.net/web_of_simplicity/lml_
pga.asp